 I would have written a shorter letter, but I did not have the time. Provincial Letters: Letter XVI, 4 December, 1656. [English Translation] Literally: I made this [letter] very long, because I did not have the leisure to make it shorter. Such statements have also been attributed to Mark Twain, T.S. Eliot, Cicero, and others besides, but this article at Quote Investigator concludes that Pascal's statement is likely the original source of the phrase.

 The secret of great fortunes without apparent cause is a crime forgotten, for it was properly done.Part IIA variant, "Behind every great fortune there is a great crime," has appeared as a quotation of Balzac; but it may have originated in a paraphrase in The Oil Barons: Men of Greed and Grandeur (1971) by Richard O'Connor, p. 47: "Balzac maintained that behind every great fortune there is a great crime."

 Nothing is so discreet as a young face, for nothing is less mobile; it has the serenity, the surface smoothness, and the freshness of a lake. There is no character in women’s faces before the age of thirty.Ch. VI: The Old Age of a Guilty Mother

 If you press me to say why I loved him, I can say no more than it was because he was he, and I was I.Variants: If a man urge me to tell wherefore I loved him, I feel it cannot be expressed but by answering: Because it was he, because it was myself.If a man should importune me to give a reason why I loved him, I find it could no otherwise be expressed, than by making answer: because it was he, because it was I.

 Thought must never submit, neither to a dogma, nor to a party, nor to a passion, nor to an interest, nor to a preconceived idea, nor to whatever it may be, save to the facts themselves, because, for thought, submission would mean ceasing to be.Speech, University of Brussels (19 November 1909), during the festival for the 75th anniversary of the university's foundation; published in Œuvres de Henri Poincaré (1956), p. 152

 La pesanteur et la grâce (1948), p. 61We believe we are rising because while keeping the same base inclinations (for instance: the desire to triumph over others) we have given them a noble object. We should, on the contrary, rise by attaching noble inclinations to lowly objects.Gravity and Grace (1972), p. 48

 Literally: I made this [letter] very long, because I did not have the leisure to make it shorter. Translation: I would have written a shorter letter, but I did not have the time. Blaise Pascal, Provincial Letters: Letter XVI, 1657 (English Translation). Often misattributed to Mark Twain, as well as T.S. Eliot, Cicero, Johann Wolfgang von Goethe, and others.